The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingData list / active test (2006/01- )
Read data list
Hint:
Using the intelligent tester's data list allows switch,
sensor, actuator and other item values to be read without
removing any parts. Reading the data list early in
troubleshooting is one way to save time.
Connect the intelligent tester (with can vim) to the
...
Disassembly
Remove radio setting condenser
Remove the bolt and condenser.
Remove oil pressure switch
Using a 24 mm deep socket wrench, remove the sensor.
Remove engine coolant temperature sensor
Using sst, remove the sensor and gasket.
Sst 09817-33190
Remove c ...
Terminals of ecu
Check occupant classification ecu
Measure the voltage of the connector.
...